Ladder



April 9, 1946. N. l.. DAHLANDER LADDERl Filed Aug. 22, 1944 n INVEN-roRNOEL L. DAHLANDER BY W ATTORNEY Patented Apr. 9, 1946 UNITED STATESPATENT OFFICE LADDER f Nox'L. Demander, New Milford, Pa.

I Application August 22, 1944, Serial No. 550,544

4 Claims.

This invention relates to ladders in general,v

both single and multiple, so extensively used today on vessels foremergency debarkation purposes.

Among the objects of the lpresent invention it is aimed to provide animproved ladder suitable not only as a single or pilots ladder, but alsoas a multiple or debarkation ladder having rigid metal rungs, exiblesuspensory elements such as chains Aand pivotal connections between thechains and the suspensory elements.

It is still another object of the present invention to provide animproved rung for a marine ladder, whether single or multiple, which mayconveniently be pivotally connected to the suspensory elements andcomposed of sheet metal folded back upon itself for reenforcementpurposes and reversible to serve as a step whether the ladder issuspended in normal position with its upper ends at the top or inreverse position with its lower ends at the top, the reversible featurebeing particularly valuable when an emergency debarkation is required atnight, at which time, in the interest of protection, as littleillumination as possible is used, with the consequent diiculty ofsecuring a ladder of this type in place if its usefulness was notsatisfactory unless suspended in one and only one way.

- It is still another object of the present invention to provide animproved rung for a marine ladder, whether single or multiple, and`converting the T-shaped construction disclosed in the co-pendingapplication for patent, Ser. No. 547,- 830, filed August 3, 1944, into areversible rung whereby the ladder equipped with such rungs may be usedwhether theV ends ofthe suspensory elements normally at the top are atthe top or at the bottom.

These and other features, capabilities and advantages of the inventionwill appear from the subjoined detail description of specifieembodimentsthereof illustrated in the accompanying drawing in which Figure 1 is afront elevation of a ladder equipped .according to one embodiment ofthis invention.

and '2 and rungs 3 pivotally connected to said Fig.,2 is a fragmentalenlarged front elevational Fig. 7 is a, fragmental diagrammatic view ofa suspensory members I and 2. The suspensory members I and 2 preferablyare lleXible and in the present instance are shown as composed of chainsof the Lock Link type connected to the lash receiving rings 4 at theirupper ends, and the chains are'preferably covered with socks orenvelopes 5 composed of a suitable fabric material such as canvas, seethe co-pending application for patent, case #12, of Frederick A. Ellis,Serial No. 547,830led August 3, 1944.

The rungs 3 in this embodiment are shown as composed of two pieces ofsheet metal 6 and 'I,

the piece 6 having a lower flange 8 folded under the tread portion 9which continues into another flange IIl and then terminates in a shankportion II. The ends, or rather edges, of the tread portion 9 with theirreenforcing anges 8 and I0, are slightly inclined toward the shankportion II as shown at I2 and I3. To this piece 6, the lpiece l,substantially identically constructed, is secured, it being secured tothe piece 6 by welding or the like. The piece 'I consists of the flangesI4 and I5,tread'portion I5 and shank portion I'I, the shank portion ,|'Ivbeing secured adjacent to the shank portion II so 'that these pieces 6and I complement one another to form an H or I formation in crosssection.

In this embodiment the loops I8 and I9 formed at the ends of the rungs 3are integral with and continuations of Athe shank portions II and I1,

respectively, the loop I8 being an integral part of the strip 20 whichis folded over and secured by a rivet 2I cr the like to the shankportions I'I and II,- the loop I9 in turn being an'integral part of thestrip 22 which is folded over and secured by a rivet 23 or the like tothe shank portions II and I1. n

Excellent results have been achieved when the rung just described iscomposed rof steel ranging from .031 to .037 inch in thickness, with thesteel being galvanized.

In the embodiment shown in Figs. 5 and 6, the loops 24 and 25 are partsof separate clips, the loop 24 having the side arms 2B and 27 and theloop 25 having the side arms 2B and 29 secured to the shankportions 30and 3l by rivets 32. Preferably, as shown in Fig. 5, two rivets 32, 32are provided for each loop forming clip 24, 25,

the Shanks 30 and 3| being portions of the piecesl 33 and 34 similar tothe portions 6 and 1, respectively, of the embodiment illustrated inFig. 3,

, except as already set forth that the loops 24, 25

are parts of separate clips in the'embodiment shown in Fig. 6 and in theembodiment shown in Fig. 3 the loops I8 and I9 are integral parts of thepieces 6 and 1, respectively.

When the loop forming clips 24, 25'are separate from the pieces 33 and34, the pieces 33 and 34 need not be welded to one another, but maydepend upon the rivets 32 for securing them to one another. Excellentresults have been of sheet steel having a thickness ranging from .031 to.037 inch and the clips forming the loops" achieved when the pieces 33and 34 are composed link portions of the suspensory members, said clipsalso having arms riveted to the ends of said shanks.

2. The combination of a plurality of suspen- 'tween tread portions, andgalvanized steel clips 24 and 25 have been composed of sheet steel Ihaving a thickness ranging from .078 to .125 inch,

and all pieces suitably galvanized.

On the other hand, excellent results have also been achieved when thepieces 33 and 34 wereV composed of sheet aluminum having a thickness ofabout .081 inch lwhen the clips forming the loops 24` and 25 would bemade of steel approximating .125 inch, with the clips galvanized.

Excellent results have also been achieved When the H or I constructionformed by the sections 33 and 34 wei'e made in one piece of aluminum,either special rolled or in a casting, having a mean thickness of .156to .162 inch.

In the embodiment shown in Fig. 7, there is illustrated a multipleladder-in which the rungs- 35 secured to the suspensory members 36,3'land 38 have the same H or I formation in cross section as theembodiments illustrated in Figs. 3 and 6. With the multiple laddertheclips forming the loops I8, i9 or 24, 25 mayeither be integral with therungfproper as shown in Fig.` 4, or separate as shown in Fig. 5. With arung having an I shape in cross section, a tread will of course be inAposition for use, that is, face upwardly whether the normal upper endsof the ladder are secured at the top or whether the normal lower ends ofthe Vladder are secured at the top, thus forming a reversible ladder`not only having all ofthe advantages of a rung T shape in crosssection, but additional advantagesflowing from the added strength thatis made pos-`A sible with an I shaped construction as compared to a Tshaped construction.

It is obvious that various changes and modiications mayv beu made to thedetails of construction without departing from the general spirit of theinvention as set Vforth in thev appended claims.

I claim: i

1. The combination of a plurality of suspensory members composed ofchain, links, rungs, each rung composed of two sheets of metal, eachsheety consisting of an upper tread portion, a short extension, and along extension,` the short extension being folded back into intimatevengagement with the-lower face of `about'one half of said treadportion, the long extension being composed of two webs lbent into'adihedral right angle, with one web folded back into intimate engagementwith the other half of the lower' -face of said tread portion, and the'other web extending at'right angles to said tread portion to form asingle thickness shank, the Shanks being at the ends of each web portionhaving loops to form journals. for parts of the chain links andmaintaining the tread portions at the top and bottom in the interest ofreversibility.

3. The combination of a plurality of suspensory members, reversiblerungs I shaped in cross section with thecross pieces formed at `the topand bottom of the intermediate web, each rung composed of rtwo sheets ofmetal, each sheet consisting of an upper tread portion, a shortextension, and a long extension, the short extension being folded backinto intimate engagement with about half of the lower face of said uppertread portion,V the long extension having two websforming a dihedralright angle with one webV folded under and in intimate engagement withthe lower face of the other half of said upper tread ,portion and theother web Vextending at right angles to said upper tread portion to forma single thickness shank, the Shanks forming anchoring means Vfor thetwo sheets of metal, and

being secured to one another in intimate engagement with one another toform an intermediatedouble thickness Webbetween the tread portions,

and clips at the ends ofthe intermediate doublev thickness web portionhaving loops forming journals 'for link portions of the suspensorylmembers, said clips -also havingA arms riveted to theY ends of, saiddouble thickness intermediate Web.

4. The'rcombination oi a plurality of flexiblesuspensory members,reversible rungs, each rung composed of two sheets of metalLeachsheetconsisting `of an upper tread portion, a shortextension, and'alongextension, the short extension havingY two webs forming a dihedral-rightangle including a long web and ashort web, thel extension having twowebs forming a dihedral right angle with one another, one we b beingfolded backvinto intimate engagement with the other half of the low-erface of the Asaid tread portion and the other web extending Aat rightanglesto said tread portionin intimate engagement with theY other web oisaid short extension,

and then extending beyond thel said short Vlex-f tension to form asingle thickness shank, the shanks forming anchoring means for thef twosheets of metal and being secured to oneanother to form "an intermediatedouble web portion'betweenfthe tread portions, and clips vat theends ofthe intermediate web portion having loops forming journals for linkportions of the 'suspensory members, Ysaid clips l'also having armsriveted lto the ends of 'saidintermediate double thicknessweb. i i .v

Y NOELL'. DAHLANDER.

